First post here, 98 Camry engine problem

Hello all,
I've been over at Toyota Nation and someone mentioned this forum so thought I'd come over here. We have a 1998 Camry with the 4cyl engine that has developed a slight knock. What is unusual is that the car belonged to my mother in law, was babied since new and serviced at the dealer. We got the car two years ago with 53K on it, and it just now turned over to 79K. We commute over 50 miles every work day so the car gets driven a lot and sometimes probably a bit harder than it should be (maybe we pushed it too hard). Last week I noticed an odd rapping sound when the engine reached about 3500-4K. Sounded like a bit of a knock so I started paying attention. Driving around normally you don't hear it but if you run it harder, bringing the RPM's up before it shifts you could hear it. My first suspicion was the beginnings of a rod bearing, given I've heard that sound before. I looked over everything under the hood to make sure nothing was loose and everything looks good. You cannot get the engine to make the noise just revving the motor, or even "power braking". Oh and I've also noticed on a cold start, it knocks lightly about four times before the oil pressure comes up. All the guys at TN think it's nearly impossible for this low mileage motor to have lower end issues unless it was run low on oil. I know for a fact it has not. We have been running Mobil one synthetic and change the oil every 3500 miles. I know one of the tell-tale tests with a rod knock is to take away the spark, once cylinder at a time. Only way I could do this, and make it knock was to pull one wire, and drive the car in low gear and listen as I bring the RPM's up. Cylinder #2 appears to be the problem. All three other ones, the knock is still there but it appears when I pulled number two, it stopped (and yes this little procedure did set the check engine light) So, that in my mind pretty much sums up that I am in a very early stage of a rod bearing failure. So what are my options..One, put a new motor in it, or two, a junk yard motor or three, try to fix it. It's a twenty year old Camry XLE..That said, the car is almost like new. Leather, paint, full power options, everything works perfect. Not your typical beat to death 1998 Camry. Car had the timing belt changed in 2008 ish, at about 50K. My father in law had it done because the car was ten years old then. I don't know if they changed anything else.
My point is I've read in various places on the web, that if you catch a bearing failure early before it bangs up the crank, often times you can get away with just replacing the bearings if the crank is smooth. It appears you can do this with this car because of the access. There are some things that I've never dealt with before, one being the balance shaft assembly, and I'm not quite rapping my head around the "1, 2 or 3" bearing thickness thing. I've read in some places, that you could have a mixture of these numbers in the same engine? Looking at bearings at places like "rockauto" they list specific thicknesses undersized like 0.25, 0.50 or 0.75 for the entire set.

I know you guys are probably going to frown on me doing this, but I'm at the point of "what have I got to lose" I've had a cascade of events this entire last month causing me to hemorrhage money, so I need to try to do this as cheap as possible. I know I can't replace the car for one in this condition for the price of an engine, but if I can get it fixed with replacing the bearings, that's a pretty cheap fix..I know it's all going to depend on the condition of the crank journal. I've read somewhere that if there are slight roughnesses, you can sometimes clean it up with crocus cloth? Oh and yes I plan to Plastigage everything to see where we are at.

Anyway if anyone can tell me what I'm about to get into as far as those odd bearing size issues and how to handle the balance shaft assembly and also, what I might look out for having never been into one of these engines, I would deeply appreciate it. Last engine I did a crank job was a Ford 390..Different animal!

The engine is VERY reliable unless over revved, overheated, run out of oil or has a lack of oil pressure.

Engine sludge can occur resulting in oil circulation problems. The sludge being caused by among other things, lack of oil changes, defective PVC system and engine design. This sludge can plug the oil pump screen and oil passages.

How often did your mother-in-law change the oil? If Toyota dealer service was always preformed, you should be able to obtain the cars past service. Determine time between oil changes.

There was a sludge US lawsuit against Toyota and an agreement reached. The car may be beyond the warranty period.

To check for sludge suggest removing the valve cover. Depending on what is found may then want to remove the pan and check for sludge on the oil pump intake screen.

Before assuming a rod bearing suggest to investigate further.

Obtain a section of rubber hose to use as a stethoscope. A rod knock is located lower on the engine block. The valve train could be making noise. It is also possible to have a loud fuel injector.

The engine can rattle with low oil pressure at start up but this is not common. Using a synthetic oil allows the use of a lower "W" weight oil which will help start up circulation issues.

Another thing to check is the balance shaft system though doubt it is the problem? The balance shaft gears are synthetic and can break down.

The system is located below the crank. The engine has a lower sub-assembly that bolts to the bottom of the block to hold the balance shaft system. The crankshaft has an integral metal gear aft of the crank snout that drives the balance shaft gears.

Inspect the crank rod journal for damage. If damaged, replacing a bearing can silence the problem but it may come back.

As to rod bearing sizing. Toyota like many engine makers, sized bearings based on actual crank and rod dimensions. They then pick a bearing from a range of bearing sizes available, not just one size as at auto parts stores..

The same sizing procedure was done for crank bearings.

Toyota marked the rod cap with 1-3 depending on big end hole size (equating to bearing clearance). One can also use a plastigage to measure rod bearing clearance. Then make a 1-3 bearing selection from a chart. This procedure is for use with standard size bearings (not oversize).

The 0.25, 0.50 are for oversize bearings used with a ground crank.

The factory shop manual has the info you need on this.

Rockauto sells only one size of a standard size bearing plus oversize bearings. The Toyota dealer should be able to obtain the wider range of standard bearing sizes used by the factory.

You will not know anything until you investigate. If the engine has sludge this will need to be cleaned out which can be a PIA.

You will need to view the rod journal and do a finger nail test to determine roughness (read up on this on the net). Crocus cloth can polish a surface but it is not going to resurface one that's damaged.

Before you take anything apart beyond the valve cover and oil pan, review the factory shop manual in detail. The rod bearings are all selected based on size and one size did not fit all.

The balance shaft had shims to set the axle clearance. You will need to reassemble using the same shims to avoid having to size them again via another chart.

Dig into the engine a little and determine what you have. Based on this make your plan.

Hi Joey,
Do you guys over here like the quotes left at the top or the bottom of posts?

thanks so much for your lengthy post and the message you sent. This issue has just got me baffled. I don't think this car has ever gone over 4K between oil changes. My father in law was fastidious about his cars, hence the reason this one still looks almost new (Sage green XLE with every option except the V-6. Even has the gold trim and wood trim package) and the oil always looks a bit darker than honey when we change it.. Over at Toyota Nation those guys swear I'm crazy for thinking that I could possibly have a rod bearing issue but given I can pull the plug wires one by one and drive the car, when pulling #2, the sound was not heard. The only way I could accomplish this test was to pull one plug wire, wrap it in a shop towel and tuck it along the valve cover and drive the car in low gear to achieve 3500-4K RPM at low speed. All but #2 I could hear the knock. The car was "driven by grandma" so to speak until we got it, but we really drive the crap out of it. Being underpowered for what we are used to, I am sure we push the car a lot. That was what I suspected happened that we worked it to death, but a guy over at TN told me it's unlikely that you could damage the engine driving it hard, with this low mileage (currently 79K)
I know every "rod bearing test" video I've seen on Youtube, they simply rev the engine with the car in park and you can hear it but I can't help but think I am at a very early stage and hopefully have not damaged the crank journal. Probably a normal person wouldn't even notice it at this point but I'm hyper sensitive to car sounds. Also the fact the car knocks about four times during cold start but I have had many cars that did that but, I don't recall ever hearing this one do it before. I know it's a lot of work to get in there but I feel that even if I just get in there and plastigage everything to see where I am. If they all pass, then there is definitely something else but what could that be, based on the plug wire test. I am a bit concerned about the balance shaft assy. I've never seen anything like that and have read of some real nightmares of guys getting it back in out of time. I saw a video a Russian guy named Peter did on Youtube, where he scribed a scratch on the crank journal to the block, and each of the two balance shafts to the body of the assy, so he could line everything back up. That seems to make sense to me. Then I read of all the guys who are taking this out altogether but that is not on my plan. I suspect I will be wanting to put the same size bearing that is in there, back in. If there is wear to have made the need for a thicker bearing, that means I will have had damage to the crank, yes? I can't imagine much normal wear at this mileage.

Anyway thanks for the tips, this has been most helpful. I really don't want to do this but I also don't want to damage the car so we've stopped driving it. It's also been a long time since I've been that deep into an engine (1966 Ford 390 crank replacement) I really want to keep this car going for another three years and never thought I would be at this place with it.

Cheers,
John

Quote:

Originally Posted by toyomoho

Welcome to CF.

The engine is VERY reliable unless over revved, overheated, run out of oil or has a lack of oil pressure.

Engine sludge can occur resulting in oil circulation problems. The sludge being caused by among other things, lack of oil changes, defective PVC system and engine design. This sludge can plug the oil pump screen and oil passages.

How often did your mother-in-law change the oil? If Toyota dealer service was always preformed, you should be able to obtain the cars past service. Determine time between oil changes.

There was a sludge US lawsuit against Toyota and an agreement reached. The car may be beyond the warranty period.

To check for sludge suggest removing the valve cover. Depending on what is found may then want to remove the pan and check for sludge on the oil pump intake screen.

Before assuming a rod bearing suggest to investigate further.

Obtain a section of rubber hose to use as a stethoscope. A rod knock is located lower on the engine block. The valve train could be making noise. It is also possible to have a loud fuel injector.

The engine can rattle with low oil pressure at start up but this is not common. Using a synthetic oil allows the use of a lower "W" weight oil which will help start up circulation issues.

Another thing to check is the balance shaft system though doubt it is the problem? The balance shaft gears are synthetic and can break down.

The system is located below the crank. The engine has a lower sub-assembly that bolts to the bottom of the block to hold the balance shaft system. The crankshaft has an integral metal gear aft of the crank snout that drives the balance shaft gears.

Inspect the crank rod journal for damage. If damaged, replacing a bearing can silence the problem but it may come back.

As to rod bearing sizing. Toyota like many engine makers, sized bearings based on actual crank and rod dimensions. They then pick a bearing from a range of bearing sizes available, not just one size as at auto parts stores..

The same sizing procedure was done for crank bearings.

Toyota marked the rod cap with 1-3 depending on big end hole size (equating to bearing clearance). One can also use a plastigage to measure rod bearing clearance. Then make a 1-3 bearing selection from a chart. This procedure is for use with standard size bearings (not oversize).

The 0.25, 0.50 are for oversize bearings used with a ground crank.

The factory shop manual has the info you need on this.

Rockauto sells only one size of a standard size bearing plus oversize bearings. The Toyota dealer should be able to obtain the wider range of standard bearing sizes used by the factory.

You will not know anything until you investigate. If the engine has sludge this will need to be cleaned out which can be a PIA.

You will need to view the rod journal and do a finger nail test to determine roughness (read up on this on the net). Crocus cloth can polish a surface but it is not going to resurface one that's damaged.

Before you take anything apart beyond the valve cover and oil pan, review the factory shop manual in detail. The rod bearings are all selected based on size and one size did not fit all.

The balance shaft had shims to set the axle clearance. You will need to reassemble using the same shims to avoid having to size them again via another chart.

Dig into the engine a little and determine what you have. Based on this make your plan.

If the problem is a rod bearing, then the sooner it is dealt with the less damage done.

A bearing can be damaged from lack oil pressure or flow. Rod bearing noise is from the bearing pounding on the crank journal. This is impact damage not wear from too many accumulated miles and engine starts.

Over time this pounding will cause journal damage that will need the crank ground or replaced. If things get bad enough the rod can come out the block.

If it's not a bearing then good news.

The 4-cylinders engine power is adequate most times but needing to put ones foot down on the gas is common in hills, when pulling a trailer, car loaded with people, etc. The issue is red lining the engine (hot rodding).

The car is a 1998 and had 53K miles when you got it 2 years ago. This means about 18-19 years to go 53K miles or less the 3K miles per year. Both time and miles are factors in oil life once exposed to the climate of an internal combustion engine.

Did you do the rubber hose stethoscope test to narrow down the noise area or eliminate areas. At least remove the valve cover (easy enough) to check for sludge.

You might try another brand of oil filter in case the current brand has a poor drain back valve design. WIX (also makes many NAPA filters) makes good aftermarket filters.

The cars fuel injectors can make a noise much like a tappet which can be be heard with the window down.

The factory manual can be confusing in the terminology and drawings. If you do take the engine apart, first obtain a marking pen of the type auto yards use to mark their used parts for sell.
Rotate the engine to TDC for the No 1 cylinder compression stroke.

When taking the engine apart mark the cam gear orientation, balance shaft gears, etc for reference. Before taking something apart reference the manual with the factory orientation markings on the gears, etc.

Some gears have more than one mark and it pays to note this now then later when trying to put the engine back together.

A few well place pen marks referencing other marks can go a long way quickly mate components. Pictures can help but make sure they are clear. Tag all electrical connections, bag items as a unit to save time finding which bolt is the correct one for this or that location.

If a bearing journal is damaged the crank may need to be ground. This means an oversize bearing. The rod big end should also be checked for distortion. There were a million plus of these engines made, parts are readily available.

It is possible to completely remove the balance shaft system but will need to plug the block oil holes. Some model cars having this engine did not come with balance system to improve throttle response.

Thanks Joey.
Haven't done the hose test yet. I've not started the engine again since my first post. Trying to eliminate more damage. I'll see if I can do that tomorrow since I'm off. Had a thought. If the bearing is bad, would that show up in one of those oil tests like Blackstone? Was thinking perhaps send away for a kit and have them analyze the oil to see what is in it? It's due for an oil change in 1K so the oil's been in there a while.
We usually use the Fram Extraguard filter and Mobil 1 10W30. Perhaps we can try a Wix and see if it eliminates the morning knock. unfortunately you can't pre-fill the filter. I thought the Extraguard filters were good ones.
I did finally figure out what that "special tool" was, it's just a 12MM, 12 point socket.
The bearing cap torque setting is really low. The manual says 18 ft-lbf and most torque wrenches start at 20 and from what I have read, they are not very accurate at the low end. Couldn't you use an inch pound torque wrench, and torque it to 216 inch pounds?

Oil changes. good points. I don't know if they did them by time/miles or just miles. If miles, likely the oil could be a couple of years old between changes. I have lots of receipts from them but I don't think I have all so I probably won't be able to figure that one out. I'll also see about pulling that valve cover off.
Thanks again for all your help!!

Call Blackstone and ask for guidance in taking the oil sample. The more miles between oil changes, the higher the readings for metals. Ask if their findings can be interpreted in terms of bearing failure.

If you change the oil/filter cut the filter can apart with tin snips and check for signs of metal.

Okay guys, I got the report back from Blackstone and it is extremely clean. In fact the person who ran the test said that the metal levels were below the average an they too feel there is no bearing failure. So, we put a new filter on it and filled it back up with oil and now the sound is more pronunced:

I couldn't hear it before just revving it. I tried the hose to the ear and couldn't pinpoint it but it seems high, like under the valve cover. Could a valve/lifter make that sound? In the video you can clearly hear it.